[yocto] Mapping root filesystem files back into packages

[Ulf Magnusson]

On Tue, Jan 19, 2016 at 10:20 AM, Paul Eggleton
<paul.eggleton at linux.intel.com> wrote:
> On Tue, 19 Jan 2016 08:31:09 Ulf Magnusson wrote:
>> On Mon, Jan 18, 2016 at 9:15 PM, Paul Eggleton
>> <paul.eggleton at linux.intel.com> wrote:
>> > On Mon, 18 Jan 2016 10:56:41 Ulf Magnusson wrote:
>> >> To support an in-house packaging format, we need to partition the root
>> >> filesystem into a number of packages (called "internal packages" from
>> >> here on to avoid confusion), where each internal package corresponds
>> >> to a number of (e.g. IPK) packages.
>> >>
>> >> The way this is currently done is by manually maintaining a database
>> >> (implemented as a PACKAGE_CLASSES class) that maps files in the root
>> >> filesystem back to packages, along with a list of what packages should
>> >> go into each internal package. I suspect it is done this way so that
>> >> post-processing steps on the root filesystem will be included in the
>> >> internal packages.
>> >>
>> >> To me this feels pretty roundabout, and I suspect that there are much
>> >> nicer solutions (suggestions welcome!). What I'm mostly curious about
>> >> at the moment though is whether there's some nicer way to map files
>> >> from the root filesystem back to packages, without having to maintain
>> >> a separate database. Having the method be independent of the package
>> >> format (e.g., IPK) would be a bonus, though I'm not sure if it's a
>> >> strict requirement.
>> >
>> > So, aside from the "internal package" concept, there are two ways to do
>> > this:
>> >
>> > 1) oe-pkgdata-util find-path - this will tell you the build-time package
>> > name that provided the specified path within the image (expects a full
>> > path, wildcards allowed). It also provides some other lookup tools. Note
>> > that this relies on pkgdata so it'll only work for a particular recipe
>> > after that recipe has been packaged.
>> >
>> > 2) Use the Toaster web UI - it allows you to browse through the image and
>> > click through from any file back to the package that contained it.
>> >
>> > Cheers,
>> > Paul
>>
>> Thanks for the hint!
>>
>> Do you have any suggestions for the other direction as well, i.e.,
>> mapping packages to files, preferably in a way that's independent of
>> the packaging format?
>
> You'd use the same mechanisms - both of the above options will let you look up
> a package and then its contents.

Could you provide an example for getting package contests via oe-pkgdata-util?
I tried

$ oe-pkgdata-util read-value
tmp/sysroots/i686-xs-baytrail-hmgua1/pkgdata/ FILES_INFO busybox
{"/bin/busybox.nosuid"

, but as seen from the output, that only gives part of the string after the
FILES_INFO key in pkgdata/runtime/busybox before the first space. I'm not
sure if that's the right key to use either.

>
>> I suspect this won't be a problem, but it shouldn't matter whether the
>> package contents are fetched from the sstate cache or not.
>
> Nope, that's not an issue.
>
> Cheers,
> Paul

Thanks,
Ulf